Spring structure



Nov. 17, 1942. s, TALLMADGE 2,302,479

SPRING STRUCTURE Filed March 17, 1941 3 Sheets-Sheet 1 'FIG.2. v

INVENTOR. E ERETT S. TALLMADGE ATTORNEYS N 1 4 E. s. TALUMADGE SPRINGSTRUCTURE- FiledvMarch 17, 1941 3 Sheets-Sheet 2 INVENTOR. E'VERETT- s.TALLMADGE BY r ATTORNEY;

Nov. 17, 1942. E. s. TALLMADGE SPRING STRUCTURE 3 Sheets-Sheet 3 FiledMarch 1'7, 1941 lOO - IOO INVENTOR.

EVERETT S. TALLMADGE m I ATT Patented Nov. 17, 1942 SPRING STRUCTUREEverett S. Tallmadge, Robbinsdale, Minn, assignor to Flexsteel SpringCorporation, Minneapolis, Minn, a corporation of Minnesota ApplicationMarch 17, 1941, Serial No. 383,838

16 Claims.

' cushioning effect.

Another object is to provide a spring structure that is strong anddurable, economical to manufacture, and efficient in operation.

Other objects, advantages and novel details o-f'construction of thisinvention will be made more apparent as this description proceeds,

especially when considered in connection with g the accompanyingdrawings, wherein:

Figure 1 is a perspective view of a spring structure embodying myinvention;

Figure 2 is a transverse sectional view taken substantially on the line2-2 of Figure 1;

Figure 3 is a longitudinal sectional view taken substantially on theline 3-3 of Figure 1;

Figure 4 is a top plan view of a slight modification;

Figure 5 is a transverse sectional view taken substantially on the line5-5 of Figure 4;

Figure 6 is a longitudinal sectional view taken substantially on theline 6-6 of Figure 4;

Figure 7 is a top plan view of another modification;

Figure 8 is a perspective view of another modification.

Referring now to the drawings, A is the frame, B is the seating surface,and C are intermediate supporting springs of a spring structureembodying my invention.

As shown, the frame A is substantially squareshape in plan and ispreferably formed from a single length of inwardly opening light weightchannel-shaped stock. At the front corners of the frame are miteredjoints l9 and II between the front crossbar l2 and the side rails l3 andit, while at substantially the center of the rear crossbar I2 the endsof the channel stock are held in abutting relation by a suitable tiebarI5 welded to said stock. The lower side it of the channel stock is widerthan the upper side ll thereof and is engageable with a suitable support(not shown) for the spring structure. In the present instance thechannel stock is curved at IS, I9, 2!! and 2|, respectively, to providerounded corners.

The seating surface B is curved both longitudinally and transverselyrelative to the frame A and preferably comprises a series ofsubstantially parallel transversely extending elongated leaf springs 22,23, 24, 25 and 26, respectively. As shown, the springs 22 and 26 are atthe front and rear of the frame and are wider than the intermediatesprings 23 to 25, inclusive. Preferably the front wide spring 22 and theadjacent intermediate spring 23 are arched across the frame and havetheir crown portions 24' and 25', respectively, substantially inalignment at approximately the longitudinal median line of the frame,while the rear wide spring 26 has a depressed portion 21 in longitudinalalignment with the crown portions 24' and 25 of the arched springs 22and 23. The intermediate spring 2A is only slightly arched across theframe, while the intermediate spring 25 is substantially straight acrossthe frame, hence the intermediate springs 23, 24 and 25, respectively,provide a stepped-down structure between the front and rear springs 22and 26. To stiffen and reinforce the structure, the leaf springs 22 to25, inclusive, have longitudinally extending embossed narrowsubstantially trough-shaped portions 28, 23, 3B and 3|, respectively,while the rear leaf spring 26 has two substantially parallel relativelylong embossed substantially trough-shaped portions 32 and 33 and isprovided at opposite ends of said embossed portions with relativelyshort embossed portions 34 and 35, respectively. The rear leaf spring 26is also provided at its rear edge with a downturned flange 36.

The intermediate supporting springs C are also leaf springs and arepreferably inverted substantially L-shape in configuration. Preferablythe upright legs 31 of the L-shaped springs are rigidly secured at theirlower ends to the side rails I3 and I4 of the frame at spaced pointsthereof, while the other legs 38 of the Us extent inwardly beneath andare secured to the leaf springs 22 to 26, inclusive, at opposite endsthereof. In the present instance, the leaf springs 22 and 23 aresupported by and secured to the forward L shaped springs C; the leafspring 24 and 25 are supported by and secured to the intermediate L-shaped springs C; and the rear leaf spring 23 is supported upon andsecured to the rear L-shaped springs C. Preferably narrow auxiliary leafsprings 39 extend along the inner edges of the forward L-shaped springsC beneath the end portions of the leaf springs 22 and the structure.

By referring to Figure 1, it will be noted that the front leaf spring 22projects forwardly beyond the front L-shaped springs C and is cut awayat and 4|, while the rear leaf spring 26 projects rearwardly beyond therear L -shaped springs C and is cutaway as at 42 and 53, respectively,to afford clearance between the end portions 44 and 45, respectively, ofsaid leaf springs and the adjacent L-shaped springs C so that the latterwill have proper freedom of movement during the flexing action of thespring structure. Thus, better flexing action is obtained as a result ofthis construction.

Actually the forward edge 55 of the front leaf spring 22 is in advanceof the front crossbar l2, and as the latter is well below and in rear ofsaid edge, there is no interference with the action of the spring otherthan to act as a safety stop under an extreme load.

The rear flanged edge 36 of the rear leaf spring 26 is curved-like andis just in advance of the rear crossbar l2 of the frame. Thus, the rear23 to strengthen leaf spring 26 is sufficiently forward of the rearcrossbar |2 and at a suitable height relative thereto to flex withoutmetal-to-metal contact. To provide the proper contour for upholsterymaterial or padding (not shown) that may be mounted on the springstructure, the opposite ends of the leaf springs 22 and 25 are roundedas at 41 and 48, respectively.

In Figures 4 to 6, inclusive, I have illustrated a slight modificationwherein the frame A is substantially square-shape in plan and ispreferably formed of two channel members and 5|, respectively. Themember 5|] is U-shape in plan and forms the front crossbar 52 and siderails 53 and 54 of the frame, while the member 5| forms the rearcrossbar of the frame and is bowed outwardly from one side rail to theother.

55 and 55, respectively, are attaching flanges or extensions projectingforwardly from opposite ends of the bowed portion 5! of the rearcrossbar and overlapping and rigidly secured to the side rails 53 and 54at their rear ends. Preferably the channel members 50 and 5| are formedof relatively light gauge metal and open inwardly. The lower sides 5!and 58, respectively,

of the channels 53 and 5| are relatively wide and z are engageable witha suitable support (not shown) for the spring structure, while the uppersides 59 and 60 of said members are narrow but adequately stiffen andreinforce said members.

In the present instance, the lower sides 5'! and 58 of the channelmembers are cut away as at BI, 62, E3 and 64, respectively, and thebases and 65, respectively, of the channel members are curved at 61, 68,69 and 10, respectively, to provide rounded corners. It will also benoted that the rear crossbar 5| is deeper than the front crossbar 52 andside rails 53 and 54. Thus, a comparatively light but sturdy and durableframe is provided.

The seating surface B is curved both longitudinally and transverselyrelative to the frame A and preferably comprises a series ofsubstantially parallel transversely extending elongated leaf springs H,12 and 13, respectively. As shown, the springs 1| and 13 are at thefront and rear of the frame and are quite wide, while the springs 12 areintermediate the spring H and i3 and are relatively narrow. In eachinstance, the springs are arched upwardly over the frame A and havetheir crown portions l4, l5

and 16, respectively, substantially in alignment at approximately thelongitudinal median line of the frame. Likewise, in each instance thecrown portions 14, 15 and 16 of the springs have upwardly embosseddownwardly opening troughshaped portions 11, T8 and 19, respectively,that extend longitudinally of the arched portions of the springs acrossthe longitudinal median line of the frame and serve to stiffen andreinforce the springs.

The intermediate supporting springs C are also leaf springs and arepreferably inverted substantially L-shaped in configuration. Preferablythe upright legs of the springs are rigidly secured at their lower endsto the rails '53 and 54 at spaced points thereof, while the other legs8| of the Ls extend inwardly beneath and con stitute supports foropposite ends of the leaf springs ll, 12 and 13, respectively. As shown,the inwardly extending legs 8| oft he Ls incline upwardly from theupright legs 80 and are preferably riveted at their inner ends of theleaf springs ll, '12 and 13, respectively. Preferably the spring TI andadjacent spring 12 are secured to the springs C at the front end of theframe; two of the springs 12 are secured to the center springs C; andthe spring 13 and adjacent spring '12 are secured to the springs C atthe rear end of the frame.

In order that the seating surface 13 will be curved longitudinally ofthe frame with the lowest part of the curve about midway the ends of theframe, the springs C at opposite ends of the frame incline toward thecenter of the frame and are spaced above the lower edges of the siderails 53 and 54, while the springs C at the center of the frame aresecured at a lower elevation so that the lower edges thereof aresubstantially flush with the lower edges of the rails 53 and 54. Thus,the springs 'H and I3 and adjacent springs l2 incline toward the centerof the frame, while the two center springs 12 are at a lower elevationand have opposite ends thereof in a common horizontal planesubstantially parallel to the rails 53 and 54.

For reinforcing the narrow leaf springs 12, I have provided supportingor secondary spring leaves D between the inturned legs 8| of the springsC and the ends of the springs 12. As shown, these secondary springleaves D are similar to those shown in my application Serial No. 338,623filed June 3, IMO, and serve the same purpose. Such spring leaves D areheld in place by the rivets 82 that secure the springs 12 to the springsC.

Preferably the wide springs H and 73 at the front and rear of thestructure overhang the L-shaped spring C to which they are secured so asto properly support upholstery material o padding therefor (not shown)of a seat construction. Actually the straight forward edge of the leafspring 7| at the front end of the str1lcture is in advance of the frontcrossbar 52. and as the latter is well below and in rear of said edge95, there is no interference with the action of the spring other than toact a safety stop under an extreme load.

The rear edge 9| of the spring l3 at the rear f the structure is curvedlike the rear crossbar 2 but terminates short thereof. Thus, the issufficiently forward of the crossbar at a suitable height relativethereto to without rnetal-to-rnetal contact.

.referably the leaf spring TI is cut on the bias at opposite endsthereof as at 92 and 93, re-

the forward end of the structure are rounded at 94 and 95, respectively.

In Figure '7 I have illustrated another modiflcation whereintwoauxiliary crossbars such as I are used in the frame construction.Preferably such bars are located in vertical alignment with openingsllll between the springs H, 12 and 13 so there will be no metal-to-metalcon tact between such springs and the auxiliary crossbars when thestructure is subjected to a normal load. However, under an extreme loadthe upholstery material or padding therefor on the springs ll, 12 and 13would rest upon the auxiliary crossbars I00 which, in such instance.would serve as a safety or limiting stop.

In Figure 8 I have illustrated another modification wherein a wire H9 ofrelatively heavy gauge is employed at the forward edge of the springstructure for engagement with the upholstery material or paddingtherefor (not shown) when it is placed upon the spring structure. Thewire has a portion Ill extending transversely across the structure inadvance of the forward L-shaped springs C to which they are secured soversely extending connecting leaf springs I I2 and H3, and is providedat opposite sides of the structur with open return-bends ll4 and I65that extend rearwardly to and are disposed upon the leaf spring H3. Forholding the wire Hi). there is a metal strip H6 at the longitudinalmedian line of the structure terminally secured to the leaf spring H3and to the portion Ill of the wire. Preferably this strip H6 extendsbeneath the leaf spring I I3 and over the leaf spring H2 and is providedintermediate its ends with a longitudinally extending substantiallytroughshaped embossed portion H! to stiffen and reinforce the same.

Many other adaptations of my invention may be made. For example, theinverted L-shape leaf springs of the type illustrated herein could beused at the rear of a seat, for example, at the rear of an automobileseat, wherein springs of other configuration, for example, C-shape ofthe type illustrated in my application Serial No. 338,623, aforesaid,may be employed at the front thereof for supporting intermediate orconnecting longitudinally extending leaf springs instead of transverselyextending springs such as 22 to 26, inclusive. In fact, the L-shapedsprings may be used on either or both sides or at either or both frontand rear portions of any supporting seat frame structure, for thepurposes herein set forth. Also, this idea could be embodied in a bedspring structure if desired.

Thus, from the foregoing, it will be apparent that each spring structurehas a saddle effect. Under a load the transversely extending leafsprings will flex at opposite ends of the embossed portions thereof,while the L-shaped springs will flex inwardly and downwardly relative tothe side rails of the supporting frame. The embossed portions of theleaf springs serve to stiffen and reinforce the structure so that itwill properly support and cushion the load. Such embossed portions donot necessarily prevent all flexing of the springs at said embossedportions.

In some instances, the embossed portions are shallow enough so thatthere is appreciable flexing at such points. The embossed portions do,however, control this flexing movement. As a result, the maximum comfortis afforded by the spring structure.

What I claim as my invention is:

1. A spring structure having a frame, and a seating surface yieldablysupported upon said frame and curved longitudinally relative to saidframe, said'seating surface consisting of a series of spacedtransversely extending leaf springs, some of said leaf springs beingarched, adjacent springs at opposite ends of the frame being inclinedtoward the center of the structure.

2. A spring structure having a frame, and a seating surface yieldablysupported upon said frame and curved transversely relative to saidframe, said seating surface consisting of a series of spacedtransversely extending leaf springs, some of said leaf springs beingarched, the leaf springs at opposite ends of the structure being widerthan the intermediate springs, one of said wide springs having amarginal downturned stiffening flange.

3. A spring structure having a frame, and a seating surface yieldablysupported upon said frame and curved both longitudinally andtransversely relative to said frame, said seating surfac consisting of aseries of spaced transversely extending leaf springs, some of said leafsprings being arched, the leaf springs at opposite ends of the structurebeing wider than the intermediate springs, the wid spring at the forwardend of the structure overhanging the front portion of the frame.

4. A spring'structure having a frame, and a seating surface yieldablysupported upon said frame and curved both longitudinally andtransversely relative to said frame, said seating surface consisting ofa series of spaced transversely extending leaf springs, some of saidleaf springs being arched, the leaf springs at opposite ends of thestructure being wider than the intermediate springs, one of said widesprings being cut on a bias at opposite ends thereof.

5.A spring structure having a frame, and a curved seating surfaceyieldably supported upon said frame, said seating surface consisting ofa series of spaced transversely extending leaf springs, some of saidleaf springs being arched, th leaf springs at opposite ends of thestructure being wider than the intermediate springs, one of said widesprings having rounded ends.

6. An all-metal seat spring structure having a seating surface curvedboth transversely and longitudinally to provide a saddle effect, a rigidbase frame, and intermediate supporting springs,

- the seating surface consisting of a series of substantially paralleltransversely extending elongated leaf springs, the transverselyextending springs at the front and rear of thestructure being wider thanthe transversely extending springs therebetween, the transverselyextending spring at the front of the structure and the transverselyextending spring next adjacent thereto being arched and having theircrown portions substantially in alignment at approximately thelongitudinal median line of the frame, the transversely extending springat the rear of the structure having a depressed portion substantially inalignment with the crown portions just mentioned, the intermediatesupporting springs being inverted substantially L-shaped leaf springsand constituting the sole supporting means for the transverselyextending springs forming said seating surface, the upright legs of theUs being secured to opposite sides of the base frame and the horizontallegs of the Ls being secured in surface-to-surface relation to thetransversely extending leaf springs at opposite ends thereof.

'7. An all-metal seat spring structure having a seating surface, a rigidbase frame, and intermediate supporting springs, the seating surfaceconsisting of a series of substantially parallel transversely extendingelongated leaf springs, the transversely extending spring at the frontof the structure and the transversely extending spring next adjacentthereto being arched and having their crown portions substantially inalignment at approximately the longitudinal median line of the frame,the transversely extending spring at the rear of the structure having adepressed portion substantially in alignment with the crown portionsjust mentioned, the intermediate supporting springs being invertedsubstantially L- shaped leaf springs and constituting the solesupporting means for the transversely extending springs forming saidseating surface, the upright legs of the Us being secured to oppositesides of the base frame and the horizontal legs of the Us being securedin surface-to-surface relation to the transversely extending leafsprings at opposite ends thereof.

8. An all-metal seat spring structure having a seating surface, a rigidbase frame, and intermediate supporting springs, the seating surfaceconsisting of a series of substantially parallel transversely extendingelongated leaf springs, the intermediate supporting springs beinginverted L-shaped leaf sprin s and constituting the sole supportingmeans for the transversely extending springs forming said seatingsurface, the upright legs of the Us being secured to opposite sides ofthe base frame and the horizontal legs of the Ls being secured insurface-to-surface relation to the transversely extending leaf springsat opposite ends thereof, the transversely extending leaf springs at thefront and rear of the structure 1 projecting outwardly beyond andoverhanging the outer edges of their supporting L-shaped springs andbeing cut away over the horizontal portions of the L-shaped springs toafford clearance between portions of said transversely extending springsand said L-shaped springs so that the latter will have freedom ofmovement during the flexing action of the spring structure.

9. An all-metal seat spring structure having a seating surface, a rigidbase frame, and inter- 1 mediate supporting springs, the seating surfaceconsisting of a series of substantially parallel transversely extendingelongated leaf springs, the intermediate supporting springs beinginverted L-shaped leaf springs and constituting the sole supportingmeans for the transversely extending springs forming said seatingsurface, the upright legs of the Us being secured to opposite sides ofthe base frame and the horizontal legs of the Us being secured insurface-to-surface relation to the transversely extending leaf springsat opposite ends thereof, the transversely extending leaf spring at thefront of the structure projecting outwardly beyond and overhanging theforward edges of its supporting L-shaped springs and being cut on thebias at opposite ends thereof so that upholstery material placed uponthe structure will not be cut by said transversely extending leaf springand the L-shaped springs will have greater freedom of movement duringthe flexing movement of the spring structure.

10. An all-metal spring structure having a frame, a transversely archedyieldable seating surface above the frame, and inverted L-shaped leafsprings carried by the frame and constituting the sole support for saidseating surface, the yieldable surface at opposite ends of the structurebeing separate leaf springs inclined toward the center thereof so thatopposite ends of the seating surface are higher than the center porticnthereof.

11. A seat spring structure having a seating surface curved bothtransversely and longitudinally to provide a saddle effect, a rigid baseframe, and intermediate supporting springs, the seating surfaceconsisting of a series of substantially parallel transversely extendingelongated leaf springs, the transversely extending spring at the frontof the structure and the transversely extending spring next adjacentthereto being arched and having their crown portions substantially inalignment at approximately the longitudinal median line of the frame,the transversely extending spring at the rear of the structure having adepressed portion substantially in alignment with the crown portionsjust mentioned, the intermediate supporting springs being invertedsubstantially L-shaped leaf springs and constituting the sole supportingmeans for the transversely extending springs forming said seatingsurface, the upright legs of the Us being secured to the base frame atopposite sides thereof, and the horizontal legs of the Ls being securedto the transversely extending leaf springs at opposite ends thereof.

12. An all-metal seat spring structure having a seating surface, a rigidbase frame, and intermediate supporting springs, the seating surfaceconsisting of a series of substantially parallel ransversely extendingelongated leaf springs, the transversely extending spring at the frontof the structure and the transversely extending spring next adjacentthereto being arched and having their crown portions substantially inalignment at approximately the longitudinal median line of the frame,the intermediate supporting springs being inverted substantiallyL-shaped leaf springs and constituting the sole supporting means for thetransversely extending springs forming said seating surface, the uprightlegs of the Us being secured to opposite sides of the base frame and thehorizontal legs of the Us being secured in surface-to-surface relationto the transversely extending leaf springs at opposite ends thereof.

13. A seat spring structure having a seating surface, a rigid baseframe, and intermediate supporting springs, the seating surfaceconsisting of a series of spaced transversely extending elongated leafsprings, some of said transversely extending springs being arched, theintermediate supporting springs being inverted substantially L-shapedleaf springs, the upright portions of the Us being secured to the baseframe at opposite sides thereof, the horizontal portions of the Usextending inwardly over the frame and being secured to the transverselyextending springs at opposite ends thereof, the transversely extendingleaf springs at opposite ends of the structure being wider than theother transversely extending springs, at least one of said wider leafsprings projecting outwardly beyond and freely overhanging the outeredges of the horizontal porsupporting said transversely extending springtions of its supporting springs.

the frame, the transversely 14. A seat spring structure having asrigidbase frame, inverted substantially L-shaped leaf springs having theupright portions thereof secured to the base frame at opposite sidesthereof, the horizontal portions of the L-shaped springs extendinginwardly over said base frame, and transversely extending leaf springsspanning the space between and terminally secured to the horizontalportions of said L-shaped springs, the transversely extending spring atthe front of the structure and the transversely extending spring nextadjacent thereto being arched and having their crown portionssubstantially in alignment at approximately the longitudinal median lineof extending spring at the rear of the structure having a depressedportion substantially in alignment'with the crown portions justmentioned.

15. A seat spring structure having a rigid base frame, invertedsubstantially L-shaped leaf springs having theupright portions thereofsocured to the base frame at opposite sides thereof, the horizontalportions of the L-shaped springs extending inwardly over said baseframe, and transversely extending leaf springs spanning the spacebetween and terminally secured to the horizontal portions of saidL-shaped springs, the transversely extending leaf spring at the fronting spring at the front of of the structure being arched and having itscrown portion at approximately the longitudinal median line of theframe, the forward portion of said transversely extending spring at thefront of the structure projecting forwardly beyond and overhanging thehorizontal portions of the foreextending inwardly over said base frame,and

transversely extending leaf springs spanning the space between andterminally secured to the horizontal portions of said L-shaped springs,the transversely extending leaf spring at the'front of the structurebeing wider than adjacent transversely extending springs and projectingforwardly beyond and overhanging the horizontal portions of the foremostL-shaped springs, the overhanging portion of the transversely extendthestructure being free to flex relative to said foremost L-shaped springs.

EVERETT S. TALLMADGE.

